I have a 1992 Dodge Cummins and have done no modifications yet. Everything stock.

I watch my fuel mileage closely (reason I bought a 1st Gen) and was getting 19-20 mpg and all of a sudden I am getting 14-15 mpg. Driving miles and speeds are exactly the same. Replaced Air and Fuel Filter with no measurable change.

Any ideas on what to look for first? It doesn't seem to run rough but not sure if this would be a good indicator for clogged injectors or not.

Just turned 130,000 miles on engine. Yes I bought from a little old man that used it once or twice a year with camper shell to Mexico for vacations. Only had 60,000 miles when I bought it in July of 2007. Very fortunate.

Thanks for any help

 

how long have you ran it after you changed the filters? The MPG will not come back instantaneously


Brice

 

deffinatley a fuel issue i think

 

Brice, has been over 6 to 7 months, mpg stays right at 14-15 mpg.

 

my friends 2nd gen did the same thing butt he bumped the timming 1/16 i think and that helped him

 

dose it smoke excessively? (worse than normal)
In a stock application smoke = restriction either intake (dirty air filter or loss of boost)
or Exhaust (plugged exhaust components)
Do you have a fuel PSI gauge?
Is your lift pump working to capacity?
Have you checked the quality of fuel your getting?
Have you cut open fuel filter to see whats inside?
Have you/do you know of any previous problems with the truck?

Brice

 

rj

 

Brice